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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
5
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pubmed:dateCreated |
1996-3-12
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pubmed:abstractText |
G protein-coupled receptors (GPCRs) have seven hydrophobic domains, which are thought to span the lipid bilayer as alpha helical transmembrane domains (TMDs). The tertiary structure of GPCRs has not been determined; however, molecular models of GPCRs have generally been based on bacteriorhodopsin, which is functionally unrelated to GPCRs but has a similar secondary structure. We sought to examine the validity of using bacteriorhodopsin as a scaffold for GPCR model building by experimentally determining the orientation of the TMDs of adrenergic receptors in the plasma membrane. In separate experiments, three sequential amino acid residues (Leu-310, Leu-311, Asn-312) in TMD VII of the beta 2 adrenoreceptors were mutated to the amino acids found in the homologous domain of the alpha 2 adrenoceptor (Phe, Phe, Phe). Exchange of Asn-312 and Leu-311 in the beta 2 adrenoceptor resulted in nonfunctional proteins, most likely due to incompatibility of the introduced bulky phenylalanine side chain with adjacent structural domains in the beta 2 adrenoreceptor. This structural incompatibility was "repaired" by replacing the specific beta 2 TMD sequence with an alpha 2 receptor sequence. TMD I and TMD II complemented the Asn-312-->Phe mutation, and TMD III and TMD VI complemented the Leu-311-->Phe mutation. These results indicate that TMDs I, II, III, and VI surround TMD VII in a counter-clockwise orientation analogous to the orientation of TMDs in bacteriorhodopsin.
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pubmed:grant | |
pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical | |
pubmed:status |
MEDLINE
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pubmed:month |
Feb
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pubmed:issn |
0021-9258
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:day |
2
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pubmed:volume |
271
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pubmed:owner |
NLM
|
pubmed:authorsComplete |
Y
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pubmed:pagination |
2387-9
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pubmed:dateRevised |
2007-11-14
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pubmed:meshHeading |
pubmed-meshheading:8576196-Animals,
pubmed-meshheading:8576196-Bacteriorhodopsins,
pubmed-meshheading:8576196-Cell Line,
pubmed-meshheading:8576196-Cloning, Molecular,
pubmed-meshheading:8576196-Humans,
pubmed-meshheading:8576196-Radioligand Assay,
pubmed-meshheading:8576196-Receptors, Adrenergic, alpha-2,
pubmed-meshheading:8576196-Receptors, Adrenergic, beta-2
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pubmed:year |
1996
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pubmed:articleTitle |
Arrangement of transmembrane domains in adrenergic receptors. Similarity to bacteriorhodopsin.
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pubmed:affiliation |
Department of Anesthesia, Stanford University, California 94305, USA.
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pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, P.H.S.
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